Email Troubleshooting

This page explains why emails from your own mail server are rejected or land in spam, and how to fix it. It covers PTR, SMTP HELO, SPF, DKIM and DMARC as well as IP blacklists, with links to step-by-step guides.

Why Do Emails End Up in Spam?

Major email providers like Gmail, Outlook, or Yahoo automatically check every incoming email against a set of criteria. If these are not met, emails are flagged as spam or rejected outright — regardless of their content. The most common causes are:

Missing or incorrect server identity

The PTR record and SMTP HELO do not match, or both point to a generic hostname provided by the hosting company.

Missing email authentication

SPF, DKIM, or DMARC are not configured — the recipient cannot verify that the email genuinely originates from your domain.

IP address on a blacklist

Your server's IP address appears on one or more public blacklists — emails are automatically rejected by receiving mail servers.

Compromised server or account

An attacker is using your server or a weak password to send spam at scale, damaging your sending reputation.

Email Authentication Checklist

For maximum deliverability, all of the following should be correctly configured. Missing entries are the most common cause of spam problems:

Record	Purpose	Priority
PTR	Maps your IP address to a hostname — the first check performed by many mail servers	Required
HELO	The name your mail server uses to identify itself — must match the PTR record	Required
SPF	Defines which servers are authorized to send emails on behalf of your domain	Required
DKIM	Adds a cryptographic signature to outgoing emails — proves authenticity and integrity	Recommended
DMARC	Defines what happens to emails that fail SPF or DKIM checks	Recommended

Since 2024, Google and Yahoo — and since 2025 also Microsoft for Outlook.com — require SPF, DKIM and DMARC for bulk senders. For all other domains, both DKIM and DMARC are strongly recommended regardless of sending volume.

Detailed Guides

Select one of the following guides for step-by-step instructions:

Configure PTR, HELO & SPF

Step-by-step guide to correctly setting up your server identity and email authentication — including DKIM and DMARC.

View Guide →

Dealing with Blacklists

Check whether your IP is on a blacklist, learn how to request removal, and prevent future listings.

View Guide →

Still having email delivery issues?

For server infrastructure related problems, our support team is available 24/7 via the PowerPanel ticket system.

Open a Support Ticket